If you want a more sustainable option (read: higher density, multi-family housing) that's actually licensed openly, checkout Eco-Libre's designs for the Launch-Nest.

• https://github.com/eco-libre/launch-nest

The structure is designed to house 30 people (18 meters x 7 meters, 5-stories high), off-grid solar PV (energy) and thermal (heating, cooking), and walls are made of CEB pressed on-site.

Eco-Libre Launch Nest

We're still in the design phase, but the FreeCAD files are public and licensed CC BY-SA.